This summary is not the rule. The rule text controls.
Here's what this rule means for your case.
If someone files a legal document (like a complaint or answer) and the other side thinks it has problems, the other side doesn't lose their right to challenge it just because they didn't file a motion to strike or dismiss it right away. In other words, staying quiet at first doesn't mean you're stuck accepting a weak or flawed pleading later on.
The rule also protects you if you did file a motion challenging the pleading, but the judge denied it. If that happens, you don't give up your right to raise the same argument again later just because you kept moving forward with the case. You're not forced to stop everything and appeal immediately. You can keep participating in the case and still bring up the same problem with the pleading at a later stage.
Basically, this rule gives people more flexibility. It means you won't automatically lose your right to challenge a bad pleading just because of timing or because you kept the case moving after an early ruling didn't go your way.